Puffing gun



Oct. 21, 1941. H. s. CROSBY ETAL 2,259,802

PUFFING GUN n 'Filed oct. r:51, 1940 s sheets-sheet 2 Thoma/5 R R oct. 21, 1941. H s CROSBY ETAL 2,259,802

PUFFING GUN Filed oct. 51, 1940 3 Sheets-Sheet 3 .I'Jzvedo l lfenry g5. (31106129 Patented Oct. 21, 1941 PUFFING GUN Henry S. Crosby, Long Lake, Minn., and Thomas P. Ring, Buffalo, N. Y., assignors to General Mills, Inc., a corporationV of Delaware Application October 31, 1940, Serial No.. 363,686

8 Claims.

This and other objects as will hereinafter ap` pear are accomplished by this invention whichv is fully described in the following specification and shown in the accompanying drawings in which Figure l is a perspective viewv of the pung gun showing parts of the carriage and jacket for the barrel cut away to show the burners;

Fig. 2 is an enlarged partial longitudinalV secv tion through the puiing gun barrel showing particularly the gas burners and the ignition device; Fig. 3 is a diagram of connections for the ignition apparatus;

Fig. 4 is a partial perspective view of the open end of the puffing gun barrel;

Fig. 5 is a section on the line 5-5 of Fig. 2;

Figs. 6 and 7 are partial enlarged sections on the lines 6 and l, respectively, of Fig. 2;

Fig. 8 is a partial enlarged perspective view of the burners; and

Fig. 9 is a cross section showing an alternative form of burner. y

This invention relates primarily to a new and eicient means for heating a puffing gun, many of the other details of the gun barrel and its mounting being old and forming the subject of separate patent applications. The gun barrel shown generally by the numeral l5 is rotatably mounted as will presently be described for rotation about its longitudinal axis in an oscillatable carriage having side channel members I6, ll, the latter being broken away, as shown in Fig. l, in order the better to show the gun barrel. These channels -are connected by end members I8, i9 and 20 and the carriage as a whole being mounted to oscillate about an axis at right angles to the longitudinal axis of the gun barrel and mounted in suitable bearings, not shown, in a main frame 2l.

Referring to Fig. 2, a gun barrel proper 30 is closed at one end by means of a gas-tight head 3l while the open end is closed by a lid 32` which is hingedly mounted on arms 33 which in turn are pivotally mounted on a pin 34, as described in detail in the patent to Thomas R. James for Puiiing gun lid release mechanism, No. 2,210,294, granted August 6, 1940. The head 3l has axially extending therefrom a shaft mounted in a suitable bearing 36 which is carried by the ca rr age member I8.

For mounting the opposite end of the gun barrel, We have provided -a ring 3l which is concentric with the gun barrel and which is secured thereto at intervals by means of a series of posts 38 which are electrically welded to the gun barrel and to the ring thereby leaving openings therebeneath for the passage of gas as will presently be seen. This ring rolls on rollers 39 journalled on pins 40 on the end member 20. When the gun is inverted this ring rests on the end member I9 but does not rotate in this position.

The gun barrel is provided with a series of outwardly projecting lugs and on each longitudinal roll of these we mount a gas burner 4B by means of laterally extending ears 4l and cap screws #8. These cap screws also pass through an insulating jacket which is preferably made up of three sections 49, 50, 5|, as shown in Fig. 5, with cover plates 52 covering the joints where these sections meet.

It will be observed that the jacket 49 is spaced from the gun barrel so as to provide an annular space 53 in which the burners are located and which serves as a combustion space for the burning gas which heats the gun barrel.

Each of these burners is provided with a series of slits which face in the one direction as shown in Figs. 6 and 8 and a series of slits 6l which face substantially at 90 therefrom. These burners are closed at both ends and these slits are preferably made with thin rotary cutters so as not to permit a 'flame to iiash back through them, the gas issuing therefrom, as will presently b: seen, being a combustible mixture.

Each of the burners is provided at its rear end with a flanged plate by means of which it is bolted to a baie ring 62 and to a pipe 65, these lpipes extending radially from 'an annular flange 66 on the end 3| of the gun barrel, this flange providing a gas space Bl. The flange 65 is ground at its end to form a gas-tight bearing with a stationary gas ring 68 which is pressed by a bearing plete 69 and a spring l0 which takes the bearing on a retaining ring 'll which surrounds andbears against a split ring 'l2 which is made up of two half circular pieces which t into a depression I3 in the shaft 35vso that when assembled the retaining ring holds the split ring 'l2 assembled on the shaft. The combustion space 53 is closed at the forward end by the baille ring 63 and is partially closed at the rear Y end by an apron 13 but communicates with the atmosphere through openings 1l and an annular space 1I.

A coibustiba mixture of gas and air is red to the gas ring 68 through a pipe Il which connects, as shown in Fig. 1, with an elbow Il, a rubber hose I2, and a pipe 83 with a connection Il which is in axial alignment with the trunnions (not shown) of the carriage and is rotatably mounted in a stationary member l5. The latter connects through a rubber hose I6 with a gas and air mixer 81 which receives air under regulated pressure through a pipe 81* and gas though a pipe 88 and a valve 89 having a lever Il within easy reach of an operator for cutting oi! heat to the putting gun while rotation of the barrel is stopped for discharging and recharging. The air continues to flow. The valve lever also carries a pin 2| which moves a lever I2 about a fulcrum 93 to open an electric switch 94 in the circuit 94 when the valve is closed. thereby stopping a motor for driving" the barrel as will later be described.

For igniting the combustible mixture we have provided a spark plug 95 which is screwed into a threaded opening 96 (Fig. 8) in one of the ears 41 so that it lies adjacent one of the burners. This spark plug has an outer metal capl'l which makes contact on each revolution of the gun barrel with a stationary brush $8 which is yieldingly mounted by means of springs 99 on a metal post |00, the latter being mounted on an ignition block on the member 2l from which it is insulated by the block IUI. The post III, however, is electrically connected to a lead Il! which connects through a secondary S of an ignition coil |03 (Fig. 3), the other side of this coil being grounded. The primary coil P of this ignition coil connects through asuitable source of alternating current IM. 'I'hus upon contact being made between the cap l1 and the stationary brushy 98, a high tension current suillcient to produce a spark across the points of the spark plug will be impressed 'upon the latter, once for eachhalf cycle of applied alternating current so long as the cap 91 remains in contact with the brush 98. This insures the combustible mixture with the annular combustion space I3 being ignited on each revolution of the gun barrel.

The rotation of the gun barrel is accomplished by means of a motor ||0 (Fig. 1) which drives through a belt a suitable reduction gearing (not shown) to a worm wheel ||2 on the shaft 35. The operation of this motor is controlled by the switch Il. Y

The lid 22 is opened by means of a trip lever which moves down beneath a trip iinger |2| when the gun barrel is tilted forward, this trip finger yielding to permit the trip lever to pass due to the action of a spring |22.

An alternative form of burner shown in Fig. 9 has been found to be particularly useful with gases of dinerent heating qualities. This consists of a rectangular tube I2 having a longitudinal slot |2| cut therein.

Across this slot is placed a longitudinally rolled or folded sheet of wire gauze |22 of about thirtyeight mesh to the inch which is held in place by a long metal strap |23 secured thereto by welding |24 at intervals on one or both sides of the strap while the latter is held firmly pressed against the rolled gauze sheet. Thus the gas and air mixture burns along both edges of the strap |23.

The other details of the pumng gun, and paraasasoa ingthegumarenotshownindetailsincethey show no part of the present invention.

While we have shown but a single embodiment of our invention. it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made which do not depart from the spirit and scope of the invention as disclosed in the appended claims.

We claim as our invention:

1. In a puiling gun, a barrel rotatable about its longitudinal axis and closed at one end, a

Y lid hinged to the barrel for closing the other end,

a heat-insulating jacket secured to and about the gun. barrel and spaced therefrom so as to provide an annular space, a plurality of spaced burners extending into this space, means for supplying a combustible mixture to said burners while the barrel is rotated, and means for igniting said mixture at the burners.

2. In a puillng gun, a barrel rotatable about its longitudinal axis and closed at one end, a lid hinged to the barrel for closing the other end, a jacket secured about the gun barrel and spaced therefrom so as to provide an annular space, a plurality of spaced burners extending into this space, said burnersbeing secured to the gun barrel and extending substantially the length of the gun barrel and having burner openings throughout substantially the length of the burners, means for supplying a combustible mixture to said burners, and means for igniting said mixture at `the burners while the barrel is rotating.

3. In a pumng gun, a barrel rotatable about its longitudinal axis and closed at one end, a lid hinged to the barrel for closing the other end, a jacket secured to the gun barrel and spaced therefrom so as to provide an annular space, a plurality of spaced burners extending into this space, the space being closed at the closed end of the barrel and open at the opposite end so that the exhaust gases pass out at the end of the barrel having the lid, means for supplying a combustible mixture to said burners, and means for igniting said mixture at .the burners.

4. In a pulng gun, a barrel rotatable about its longitudinal axis and closed at one end, a lid hinged to the barrel for closing the other end, a jacket secured to the gun barrel and spaced therefrom so asfto provide an annular space,

, a plurality of spaced burners extending into this space, means for supplying a combustible mixture to said burners, and means carried by the barrel for igniting the combustible mixture.

5. In a puiiing gun, a barrel rotatable about its longitudinal axis and closed at one end, a

Y lid hinged to the barrel for closing the other end,

a jacket secured to the gun barrel and spaced therefrom so as to provide an annular space, a plurality of spaced burners extending into this space, means for supplying a combustible mixture to said burners, and high tension electric means carried by the barrel for igniting the combustible mixture.

6. In a puiilng gun, a barrel rotatable about its longitudinal axis and closed at one end, a lid hinged to the barrel for closing the other end, a jacket secured to the gun barrel and spaced therefrom so as to provide an annular space, a plurality of spaced burners extending into this space, means for supplying a combustible mixture to said burners, and high tension electric means carried by the barrel for igniting the comticularly the method of loading, closing and rbustible mixture on each revolution of the barrel,

said means including a stationary insulated brush, and a spark plug having spaced electrodes extending into said space and a metal` cap adapted to engage the brush on each revolution of the barrel.

'7. In a pumng gun, a barrel rotatable about its longitudinal axis and closed at one end,A a lid hinged to the barrel for closing the other end, a jacket secured to the gun barrel and spaced v therefrom so as to provide an annular space, a plurality of spaced burners extending into this space, means including parts located'about the axis of the barrel for supplying a combustible mixture to said burners, and means for igniting said mixture. I

, 8. In a puffing gun, a barrel rotatable about its longitudinal axis and closed at one end, a lid hinged to the barrel yfor closing the other end, a jacket secured to the gun barrel and spaced therefrom by means of bosses integral with the barrel so as to provide an annular space, a plurality of spaced burners extending into this space, and means for supplying a combustible mixture to said burners.

I-IENRY S. CROSBY.

THOMAS P. RING. 

